Prince Rihit and the gardener's son, Jooin, grew up together despite their different social classes. Jooin, a beta and a commoner, has had a crush on Rihit, an alpha of royal blood, for a long time. However, Jooin knows that this love can never bloom since the prince must marry an omega and succeed the throne. Jooin eventually leaves Rihit's side, despite Rihit's request to have Jooin stay beside him as his Dongsaeng for the rest of his life. Three years later, Jooin returns to the castle. Unable to overcome his feelings for the prince, Jooin becomes Rihit's butler once again. Rihit never tried searching for Jooin after his departure. Jooin knows that their relationship won't be the same as before, but with Rihit's mysterious attitude, Jooin becomes more and more involved with him...